Alucard again, yay!
I loved Sebastian's reaction over the elder vampire. What I don't get is Seras' reaction, she's more noisy in the manga. I think you portait Alucard just fine, but maybe a little more talk with Sebastian is in the order.

Nice POV. I like how you portayed Seras, very in character.
This means Sebastian has a twin sister and both were vampires since birth? Sorry, a little confused in here.
Anyway it's getting better. Keep with the good writing.

This is awesome! Sebastian is a character yet to know from the first chapter but he looks promising (as long as doesn't end like a copy of Alucard). I loved the narrative and the battle is well detailed.
If it's 30 years in the future, what happened with Seras? I hope she's still at Hellsing's service.
Anyway, keep going with the story. Please? :)